Anchoring plug



Aug. 4, 193.1. w 1,817,790

- ANCHORING PLUG Filed March 18, 1929 INVENTOR.

.20 Therefore the present invention has greater drel and re-set-up the machine, all of which atented Aug. 4, 1931 I v UNITED STATES PATENT OFFICE EDWIN JAMES WHIFFEN, OF MOUNT. VERNON, NEW YORk ANCHORING PLUG Application filed March 18, 1929. SeriaI No. 348,049.

The invention relates to plugs, made from It is this part of the mandrel located in the stranded fibrous material and a cement, oven that-causes tubular plugs tolbe more used to form an anchorage for screws, nails, difiicult and expensiveoto manufacture than or the like when inserted in prepared .holes the present invention. As the product in stone, concrete, brick, glass, metal or passes thru the oven some of the cement adother hard material. heres to the mandrel and is baked on. The Plugs of this general type have heretofrictional drag due to the cement coating fore been tubular. The reason for this has baked on the mandrel may become great been to provide a means of guiding the enough to overcome the pulling power 0 screw and keeping it in the center of the the drawing-in rollers. In this case the plug. The present invention has no center product stands still in the ovenwand a burnhole. It is so made that the core is not so up is sure to follow if the machine is not thoroly impregnated with cement as is the immediately tended and the mandrel withouter portion of the plug. A plug so made drawn and cleaned. This limits the nurn- 15 guides and centers the screw equally as well ber of machines one operator can tend, makas a tubular plug does. ing the labor cost greater than in the manu- Within certain limits the holding power facture of the present invention, in which of a fibre screw anchor is proportional to no mandrel is required. If there is a the amount of material in that anchor. burn-up, it is necessary to clean the manholding power than the tubular forms of adds to the labor cost besides stopping proplugs made of the same kind of material duction. It sometimes happens that the compressed to the same degree, because the coating of cement on the. mandrel splits the volume of a solid cylindrical form is greater product instead of stopping it. The split 25 than that ofany possible tubular form of plugs so made are thrown away as waste the same outside dimensions. for they are even more fragile than the reg- 7 Besides greater holding power, another ular product.

advantage of the present invention is the Another advantage of the solid plug, the ease with which a means of lubricating the present invention, is that it is not so fragile 30 screwmay be incorporated. By impregas the tubular plug. It can stand contact nating the core of the plug with a lubricant with heavy obgects without becoming so as the plug is being made, it is possible to crushed and broken as to be useless. have a plug, the lubricant in which will not Still another advantage of the present in dry up nor shake out during the transporvention is that solid plugs may be coated tation and handling of the plug after it is with shellac, varnish, or other material made and before 1t is used as a screw without possibility of filling any center hole anchor. and thus destroying the screw-guiding Another advantage of the present invenproperties. Such a coating gives an imtion is the ease and economy of manufacproved appearance to the plug and helps it ture. This is due to the fact that no manresist moisture. In some cases such a coatdrel is required. In the manufacture of ing increases the holding power of the plug, tubular plugs 'a. mandrel is used to form the In the accompanying drawing is illustratcenter hole. After the product is shaped ed one form of this invention. The drawinto a tubular form it is drawn thrir a ing shows a plug in which the core A is sur- 45 drying oven which sets the cement. The rounded by strands B parallel to the core. mandrel must'be long enough to insure that It is also possible to make a plug with the the product has set to the required tubular outer strands B either laid spirally about form before it reaches the end of the mancore A or plaited about such core. If two drel. This means that the mandrel must or more layers of outer strands B are used extend well into, or thru, the drying oven. in making the plug such layers may be arranged in any combination desired, for example, a layer of parallel strands about the core in turn surrounded by plaited strands. In any case the strands B are joined to each 5 other and to the core A by means of a cement. The core A may be of untreated fibrous material or the material may be impregnated with a lubricant. It is also possible to make plu s in which the outer m strands B are joine I to each other but not to the core A by means of a cement.

One method of making this invention is to draw oil from a spool the fibrous material which forms the core, this material may be lubricant treated or not as may be desired. This core is then surrounded by other strands which have been drawn from spools and-impregnated with a cement. The whole is drawn through a die to scrape off the exgo ces's cement and is then drawn through heated dies in a drying oven to dry and set the product. The purpose of the heated dies, besides helping dry the roduct, is to-hold the product together until the setting of the cement has bound the product together. With some kinds of cement the heated dies are not necessary merely running the roduct through the drying oven being s cient to dry and set the product in the required .7 form. After being drawn through the oven the product may be cut into plugs of the de sire length by means of a cutter. Grooved rollers form a satisfactory means of drawing the product'through to the cutter. a

as I claim:'

1 A plug, made of stranded fibrous materlal and a cement, and having a solid core less firm than the outer portion.

- 2. A plug, made of stranded fibrous ma- 40 terial and a cement, and having a solid core lubricant impregnated, said core being less 'firm than the outer ortion.

EDWIN fAMES WHIFFEN. 

